This position detection system comprises a mobile station that transmits a beacon signal, a plurality of fixed stations that receive the beacon signal, and a position analysis device that acquires position information for the mobile station by estimating the position of the mobile station from the reception intensities of the beacon signal at each fixed station. The mobile station includes a movement detection unit (acceleration sensor, geomagnetic sensor, etc.) that determines when movement has stopped. While the movement of the mobile station has stopped, the position analysis device stops estimating the position of the mobile station and keeps the position information at a fixed position.